Update calls to/uses of LTTng-UST API

Ubuntu 22.04 (for ROS 2 Humble in May 2022) will probably have LTTng-UST 2.13.

Althought it's still backwards-compatible, macros and functions were renamed to add a LTTNG_UST_/lttng_ust_ prefix, e.g.:

  • tracepoint() -> lttng_ust_tracepoint()
  • TRACEPOINT_EVENT() -> LTTNG_UST_TRACEPOINT_EVENT()

see:

Edited by Christophe Bédard